Microsoft unveiled its long-awaited Windows Phone 7 Series on Monday, finally giving the world a glimpse of its answer to mobile competitors' touchscreen phones as well as an introduction to the smartphone operating system's new name.

At the press conference, held at this week's Mobile World Congress (MWC) in Barcelona, Spain, Microsoft (NASDAQ: MSFT) CEO Steve Ballmer said that the "7 Series" phones will be available at retail in time for the 2010 holiday season.

Officials also named a list of partners, including mobile operators as well as handset manufacturers that will build the 7 Series. On the list of operators that will be partnering with Microsoft to provide phones to customers as well as software and services are AT&T, Deutsche Telekom AG, Orange, SFR, Sprint, Telecom Italia, Telefonica, Telstra, T-Mobile USA, Verizon Wireless and Vodafone.

Senior Vice President Andy Lees of Microsoft's mobile communications business also announced that it is investing in joint projects with two of the mobile operators -- AT&T and Orange -- to bring "a full Windows Phone 7 Series experience to the market across a range of phones."

He did not elaborate on what the efforts might entail, however.

It's no accident that Microsoft singled out AT&T, since it is so far the exclusive partner for Apple's (NASDAQ: AAPLE) iPhone in the U.S. It was also the first to deliver smartphones based on Windows Mobile -- the current version of its smartphone software -- into the U.S. market in 2003. Orange, meanwhile, was the first operator to offer Windows Mobile smartphones in 2002, Leeds added.

The 7 Series devices will also have three dedicated hardware buttons that are controlled by the operating system -- home, back, and Bing search.

Additionally, Microsoft will provide a 7 Series version of Office and the Outlook mail client, and a large portion of Microsoft's emphasis is on consistency of the UI in order to provide users with an integrated experience, officials said.

"Internet Explorer [on 7 Series] is based on the desktop IE code [and Outlook] works just like Outlook on the desktop," Joe Belfiore, corporate vice president for Windows Phone program management," told the gathered press.

As far as hardware specifications, 7 Series devices will support a four-point multitouch UI.

Perhaps one disappointment for some potential customers is that 7 Series devices will lack support for Adobe Flash.

"We have no objection to Adobe Flash support, but in [version 1] there will be no support," Ballmer told a questioner at the end of the press conference.

As for futures, Microsoft officials said that the company will be gradually revealing more regarding 7 Series over coming months.